Impeller, particularly with one or more channels



Feb. 15, 1966 c GROSSKQPF 3,234,887

IMPELLER, PARTICULARLY WITH ONE OR MORE CHANNELS Filed Dec. 24, 1963 2 Sheets-Sheet 1 %...AZM

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Feb. 15, 1966 c. B. GROSSKOPF 3,234,837

IMPELLER, PARTICULARLY WITH ONE OR MORE CHANNELS Filed Dec. 24, 1963 2 Sheets-Sheet z Fig. 8 Fig.10

IN VENTOR' United States Patent Ofitice 3,234,887 Patented Feb. 15, 1966 3,234,887 IMPELLER, PARTICULARLY WITH ONE OR MORE CHANNELS Carl Bruno Grosskopf, Hambnrg-Othmarschen, Germany, assignor to Aktiebolaget Flygts Pumpar, Stockholm, Sweden Filed Dec. 24, 1963, Ser. No. 333,011 Claims priority, application Germany, Jan. 5, H63, E 24,128; July 19, 1963, E 25,184 8 Claims. (Cl. 1(l3115) Impellers with not more than two blades for pumping composite mediums such as sludgy waste water, drippy mediums carrying solid particles or the like are known. A disadvantage with such impellers is, that they very quickly wear out when abrasive compositions are pumped and that they are not suitable for pumping media containing gaseous occlusions or similar substances.

The present invention has among its objects to avoid such inconveniences and it broadly provides that the blades of the impeller, which are curved convexly helically and which extend over a substantial part of the periphery angle of the impeller, preferably at their inside, are provided with disengagement-forcing steps; furthermore, that the surfaces of the blades in connection with said steps are arranged in such a way, that an extension of the blade surface just before each step in the flowthrough direction is divergent in relation to the blade surface just after the step, the solid particles in the medium being thus prevented from striking the blade surface after the steps. Said steps may be arranged either substantially in the axial flow-through direction or arranged perpendicularly to said axial flow-through direction. It is also possible to bend out the out-flow edge of each blade in a diifusor like manner so as to form a disengage-ment-forcing step.

If several steps are arranged in the flow-through direction it may also be suitable to arrange them diametrically with respect to each other and it is also possible to carry out the different steps between the inand outflow of the impeller with diiferent heights. According to the invention one may also make said steps exchangeable and also carry them out in a plastic material.

In order to further improve the possibility to keep the solid particles suspended in the carrying liquid, which is for instance also a problem in the food industry, according to the invention there is further provided a whirl creating element within the spacing of the onebladed impeller, such as for instance a vortex impeller with substantially radial or curved blades. Said element thus creates a whirl in the impeller space, which makes it easier to keep the solid particles suspended in the carrying liquid, thus enabling them to pass through the oneblade impeller space in a free flow together with the carrying liquid.

The vortex creating element is preferably arranged at the pressure side or bearing side of the impeller and may be provided in a recess of the bearing wall, whereby the borders of the recess will form a limitation at the periphery of the vortex generating impeller.

It is suitable to execute the vortex generating element as an exchangeable impeller positioned on an inner axis rotatably mounted in the hollow axis of the oneblade impeller. Further the vortex generating element too may be composed of elastic material.

The invention will now be described more in detail with reference to the accompanying drawings in which:

FIG. 1 is a sectional view of a one-channel impeller with a step-shaped disengagement-forcing inflow edge and a step-shaped profile particularly the inside of the blade, the two means forcing disengagement being positioned approximately radially opposite each other;

FIG. 2 is a fragmentary sectional view of a flow threshold;

FIG. 3 is a fragmentary sectional view of a blade outflow edge which is expanded with the purpose of causing disengagement;

FIG. 4 is an elevational view of a one-channel impeller in accordance with the invention having disengagement forcing steps at right angles to the system axis;

FIGS. 5 and 7 are fragmentary sectional views of twochannel impellers, which are by way of example provided with blades opposite each other;

FIG. 6 is a fragmentary sectional view of an S-shaped blade and disengagement-forcing means on the pressure side of said blade and on the sub-pressure side, respectivey;

FIG. 8 is a sectional view of a one-channel impeller and a one-blade impeller, respectively, having a substantially smooth or flat interior spacing limitation on the pressure side and the bearing side, respectively, the blade sections of the vortex generator being retracted somewhat behind the plane of the wall;

FIG. 9 is a sectional view of a blade in a one-channel impeller with axial' disengagement-forcing profiles in the blade mantle;

FIG. 10 is a fragmentary schematic view of a vortex generator having straight radial blades;

FIG. 11 is a fragmentary sectional view of the vortex generator positioned in a recess in the wall of the pressure side and bearing side, respectively, of a one-channel impeller, wherein said blades can be curved;

FIG. 12 is a schematic view of a one-channel impeller with curved blades;

FIG. 13 is a sectional view, similar to FIG. 11, but showing a modication wherein a one-channel impeller with a vortex generator is provided behind the wall plane and with the circumferential surfaces of the vortex generator wall passing successively into the interior blade surfaces of the one-channel impeller; and

FIG. 14 is a sectional view of a further modified vortex generator in front of the wall plane of the pressure side and the bearing side, respectively, and having its circumferential outflow edges bounded by headbandresembling damming means or the like, which are fixed in position or rotatable.

In the figures the designation 1 refers to a blade which is helically curved outwards and provided with an inflow edge 2 and a disengagement-forcing step 3 as an example situated opposite the step 4 serving for disengagement, the outflow direction 5 of which diverges with respect to the adjacent blade surface 6. As an example the designation 7 refers to a disengagementforcing step on the outside of the blade. The designation 8 refers to a profile in the form of a flow threshold.

FIGURE 3 shows a blade 9 provided with an outflow edge 10, which is bent or curved outwards an angle on for the purpose of causing disengage-ment.

In FIGURE 4 the designations 1-1, 12 and 13 refer to the axial or inclined inflow surfaces of a one-channel impeller. Together with the remainder of the blade surface 14 these surfaces form the disengagement-forcing steps 15 lying at right angles to the flow-through direction, the outflow direction of said steps being designated 16. The blade outflow edge which is curved outwardly is designated 17. The designations 18 and 19 (FIGURE 5) refer to the blades in a two-channel impeller having diametrically opposed steps wherein the outflow directions are designated 20 and are divergent with respect to the surfaces of the adjacent blade portions. The designations 21 and 22 refer to the blades of a two-channel impeller having profiled blade inflow edges which are positioned adjacent each other mounthpiecelike. An S-shaped blade 28 (FIGURE 6) is provided with disengagementcurved shape.

3 forcing means 24 on the pressure side and corresponding means 25 on the suction side. In FIGURE 8 the impeller hub is designated 26, the single blade in a one-channel impeller is designated 27, and 28 is the outflow edge of said blade. The designation 29 refers to a vortex generator with impeller blades 30 and a radial guard plate 31 at the impeller hub. The designation 32 refers to a vortex generator provided with damming surfaces 33 and positioned in a recess. The vortex generator blades 34, FIGUREIZ, are as an example shown having The designation 35 refers to a vortex generator situated in the impeller wheel on the pressure side and substantially behind the impeller plane 36. A

vortex generator freely positioned in the impeller spacing is designated '37, 38 is its radial guard plate and 39 is a circumferential boundary ring. The diameters of the inflow connection of the pump housing to the one-channel impeller and the cylindrical inflow portion of a one-channel impeller, respectively, are designated d.

The figures in the accompanying drawings are intended only to illustrate examples of the invention, which can be applied in many other embodiments and combinations thanthose shown above, thereby making it possible to provide other shapes and types of impellers for centrifugal pumps, above all for pumping compositions containing slimy and sludgy material, abrasive particles etc.

I claim:

1. In a one blade-impeller for pumping composite media comprising an impeller blade which is curved convexly helically and which extends over a substantial part of the periphery angle of the impeller and which further at its inside is provided with disengagement-forcing steps having a surface just before each step which, ifextended in the flow-through direction, Wouldbe divergent with respect to the blade surface just after said step, the arrangement of a vortex generating element lying within the impeller blade spacing, said vortex generating element being shaped as an impeller with substantially radially positioned-blades and being furthermore positioned on the impeller wall situated on the bear-ing side of the impeller.

2. In a one-bladeim'peller for pumping composite media comprising an impeller blade which is curved convexly helically and which extends over a substantial part of the periphery angle of the impeller and which further at its inside is provided with disengagement-forcing steps having a surface just before each step which, if extended in the flow-through direction, would be divergent With respect to the blade surface just after said step, the arrangement of a vortex generating element lying within the impeller blade spacing, said vortex generating element being shaped as an impeller with substantially radially positioned blades, said vortex generating element being arranged in a recess in the bearing side wall of the impeller, the borders of said recess forming a limitation at the periphery of the vortexgenerating element.

3. In a one-blade-impeller for pumping composite media comprising an impeller blade which is curved convexly helically and which extends over a substantial part of the periphery angle of the impeller and which further at its inside is provided with disengagement-forcing steps having a surface just before each step which, if extended in the flow-through direction, would be divergent with respect to the blade surface just after said step, the arrangement of a vortex generating elementlying within the impeller blade spacing, said vortex generating element being shaped as an impeller with substantially radially positioned blades, said vortex generating element comprising an exchangeable impeller which is positioned on an inner axis rotatably mounted in a hollow driving axis of the one-blade impeller.

4. In a one-bladeimpeller for pumping composite media comprising an impeller blade which is curved convexly helically and which extends over a substantial part of the periphery angle of the impeller and which further at its inside is provided with disengagement-forcing steps having a surface just before each step which, if extended in the flow-through direction, would be divergent with respect to the blade surface just after saidstep, the arrangement of a vortex generating element lying within the impeller blade spacing, said vortex generating element being shaped as an impeller with substantially radially positioned blades, said vortex generating element being composed of an exchangeable impeller comprising elastic material.

5. A one-blade impeller for pumping composite media, comprising an impeller blade which is curved convexly helically and which extends over a substantial part of the periphery angle of the impeller, said impeller blade being provided with disengagement-forcing steps, the blade surface in connection with said steps being arranged in such a way, that an extension of the blade surface just before a step in the flow-through direction is divergent with respect to the blade surface just after said step, the solid particles in the medium thereby being restrained from striking the blade surface after the steps.

6. An impeller according to claim 5, in which the disengagement-forcing steps are arranged substantially in the axial direction of the impeller.

7. An impeller according to claim 5, in Which the out-flow-edge of the blade is bent out in a diifusor-like manner, so as to form a disengagement-forcing-step.

8. An impeller according to claim 5, in which the disengagement-forcing steps between the inflow and outflow have different step heights.

References Cited hy'the Examiner UNITED STATES PATENTS 1,688,345 10/1928 Mursch et al 103-115 2,236,706 4/1941 Damonte 103115 2,737,898 3/1956 Andermatt et a1 103-115 2,887,958 5/ 1959 Davidson 103115 FOREIGN PATENTS 65,687 1914 Austria. 503,332. 5/1954 Canada. 655,826 1/1938 Germany. 1,020,868 12/1957 Germany. 1,042,384 10/1958 Germany.

365,817 1/1932 Great Britain. 725,909 3/1955 Great Britain. 928,416 6/1963 Great Britain.

DONLEY J. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Examiner. 

1. IN A ONE-BLADE-IMPELLER FOR PUMPING COMPOSITE MEDIA COMPRISING AN IMPELLER BLADE WHICH IS CURVED CONVEXLY HELICALLY AND WHICH EXTENDS OVER A SUBSTANTIAL PART OF THE PERIPHERY ANGLE TO THE IMPELLER AND WHICH FURTHER AT ITS INSIDE IS PROVIDED WITH DISENGAGEMENT-FORCING STEPS HAVING A SURFACE JUST BEFORE EACH STEP WHICH, IF EXTENDED IN THE FLOW-THROUGH DIRECTION, WOULD BE DIVERGENT WITH RESPECT TO THE BLADE SURFACE JUST AFTER SAID STEP, THE ARRANGEMENT OF A VORTEX GENERATING ELEMENT LYING WITHIN THE IMPELLER BLADE SPACING, SAID VORTEX GENERATING ELEMENT BEING SHAPED AS AN IMPELLER WITH SUBSTANTIALLY RADIALLY POSITIONED BLADES AND BEING FURTHERMORE POSITIONED ON THE IMPELLER WALL SITUATED ON THE BEARING SIDE OF THE IMPELLER. 